Question

Learn with an example
Find (fog)(x).
f(x) = 5x
g(x) = 4x
Write your answer as a polynomial in simplest form.
(fºg)(x) = 1
Submit
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Composition of linear and quadratic functions: find an equation

Answer 1

Answer:

$\large{\textbf{f(g(x)) = 20}\\}$

Step-by-step explanation:

$\large{\textup{Given}:\\ f(x) = 5x \hspace{5mm} \& \hspace{5mm} g(x) = 4x \\ f \circ g(x) = f(g(x))   \\ \implies f(g(x)) = f(5x) \\\textup{i.e., To substitute 5x instead of x in f(x) }\\ \implies f(5(x)) = 4(5(x)) = 20x \\ \textup{Now,} f(g(1)) = 20(1) =20 }$